import re
from random import randint
from typing import Any, Dict, Optional
import urllib
import poplib
from appPublic.log import debug
from appPublic.dictObject import DictObject
from appPublic.timeUtils import curDateString, timestampstr
from email.parser import Parser
from email.header import decode_header
from email.utils import parseaddr
from ..core import Gateway


def guess_charset(msg):
	charset = msg.get_charset()
	if charset is None:
		content_type = msg.get('Content-Type', '').lower()
		pos = content_type.find('charset=')
		if pos >= 0:
			charset = content_type[pos + 8:].strip()
	return charset

class EmailClient:
	def __init__(self, pop3_server, emailaddress, password):
		self.client = poplib.POP3(pop3_server)
		self.client.user(emailaddress)
		self.client.pass_(password)

	def stat(self):
		return self.client.stat()
	
	def mail_list(self):
		resp, mails, octets = self.client.list()
	
	def get_mail(self, index):
		resp, lines, octets = self.client.retr(index)
		debug(f'{resp=}, {octets=}')
		msg_content = b'\r\n'.join(lines).decode('utf-8')
		msg = Parser().parsestr(msg_content)
		mail = {
			"mailfrom": msg.get('From'),
			"mailto": msg.get('To'),
			"subject": msg.get('Subject'),
			"body": self.get_body(msg)
		}
		return DictObject(**mail)
	
	def get_body(self, msg):
		if msg.is_multipart():
			parts = msg.get_payload()
			content = ''
			for part in parts:
				content += self.get_body(part)
			return content
		else:
			content_type = msg.get_content_type()
			content = msg.get_payload(decode=True)
			charset = guess_charset(msg)
			if charset:
				content = content.decode(charset)
			else:
				content = content.decode('utf-8')
			return content

class TransferGateway(Gateway):
	def __init__(self, from_mail="", pop3server="", email="", password="", account_no=""):
		self.from_email = from_email
		self.pop3server = pop3server
		self.email = email
		self.password = password
		self.account_no = account_no
		self.running = False
	
	async def new_tcode(self, sor):
		tcode = self.gen_mailcode()
		sql = "select * from transfercode where tcode=${tcode}$ and status='0'"
		while True:
			recs = await sor.sqlExe(sql, {'tcode': tcode})
			if len(recs) == 0:
				break
			tcode = self.gen_mailcode()
		return tcode

	async def create_payment(self, payload: Dict[str, Any]) -> str:
		"""
		返回一个可以在 H5 里直接重定向的支付宝支付 URL
		"""
		ns = {
			"id": payload.out_trade_no,
			"customerid": payload.customerid,
			"amount": payload.amount,
			"curdate": curDateString(),
			"curtime": timestampstr(),
			"status": '0'
		}
		ns = DictObject(**ns)
		ns.account_no = self.account_no
		env = payload.request._run_ns
		db = DBPools()
		dbname = env.get_module_dbname('unipay')
		async with db.sqlorContext(dbname) as sor:
			sql = "select * from transfercode where tcode=${tcode}$ and status='0'"
			ns.tcoce = await self.new_tcode(sor)
			await sor.C('transfercode', ns.copy())
			url = env.entire_url('transfer_info.ui')
			query_str = urllib.parse.urlencode(ns)
			return f'{url}?{query_str}'
		return None

	def get_transfer_data(self, mail):
		assert mail.mailfrom == '95555@message.cmbchina.com'
		assert mail.mailto == self.email
		assert mail.body.startswith('动账业务通知')
		ns = DictObject()
		match = re.search(r'交易金额\s*[:：]?\s*(\d+(?:\.\d+)?)', mail.body)
		if match:
			ns.amount = float(match.group(1))
		p =  r'摘要[:：]\s*(\d{7})(?!\d)'
		match = re.search(r'摘要[:：]\s*(\d{7})(?!\d)', mail.body)
		if match:
			ns.code = match.group(1)
		assert ns.amount
		assert ns.code
		return ns
	
	def gen_mailcode(self):
		c = '1'
		for i in range(6):
			c += randint(0,9)
		return c
		
	def run(self):
		self.running = True
		while self.running:
			ec = EmailClient(self.pop3server, self.email, self.password)
			mail = ec.get_mail(1)
			
	async def query(self, out_trade_no: str) -> Dict[str, Any]:
		pass
	
	async def refund(self, *, out_trade_no: str, refund_amount: str, out_request_no: str) -> Dict[str, Any]:
		pass
	
	async def handle_notify(self, request) -> Dict[str, Any]:
		pass